The present invention relates to novel alkylphenol-aldehyde resins which can be used in particular as wax anti-settling additives for oils and oil distillates and in particular for motor fuels and liquid hydrocarbon fuels.
The alkylphenol-aldehyde resins originating from the condensation of alkyl phenol and aldehyde have been known for a long time as agents for improving the flow of mineral oils. See for example, EP 311 452 which describes condensation products of at least 80% mol of dialkylphenols and aldehydes having 1 to 30 carbon atoms; EP 857 776 which describes the use of alkylphenol-aldehyde resins in which the alkyl groups of alkylphenol have 4 to 12 carbon atoms and the aldehyde has 1 to 4 carbon atoms and containing no more than 10% mol of alkylphenols having more than one alkyl group, in combination with ethylene/vinyl ester co- or ter-polymers for improving the fluidity of mineral oils; and EP 1 584 673 which describes alkylphenol-aldehyde resins of Mn between 1000 and 3000 originating from the condensation of a C1-C4 aldehyde and a mixture of alkylphenols with a majority of monoalkylphenol, the alkyl group having 1 to 20 carbon atoms intended to improve the low temperature flow properties of motor fuel compositions. Modified alkylphenol-aldehyde resins have also been proposed as additives for improving the low temperature flow of mineral oils; EP 1 767 610 describes alkylphenol resins, the condensation reaction of which with the aldehydes is carried out in the presence of fatty acids having 2 to 50 carbon atoms, or their derivatives, such as esters.
The present invention proposes novel modified alkylphenol-aldehyde resins which can be used for improving the low temperature stability of motor fuels and liquid hydrocarbon fuels and more particularly the low temperature flow by limiting the settling of waxes contained in the motor fuels and liquid fuels. The modified alkylphenol-aldehyde resins according to the invention can be obtained by a Mannich reaction of an alkylphenol-aldehyde condensation resin                with at least one aldehyde and/or one ketone having 1 to 8 carbon atoms, preferably having 1 to 4 carbon atoms;        and at least one hydrocarbon compound having at least one alkylmonoamine or alkylpolyamine group (i.e. having several amine groups) having between 4 and 30 carbon atoms, called hereafter alkylamine,        the alkylphenol-aldehyde condensation resin can itself be obtained by condensation        of at least one alkylphenol substituted by at least one linear or branched alkyl group having 1 to 30 carbon atoms, preferably a monoalkylphenol,        with at least one aldehyde and/or one ketone having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms.        
The alkylphenol-aldehyde resins are known per se. According to a preferred embodiment, the modified alkylphenol-aldehyde resins according to the invention can be obtained from at least one alkylphenol substituted in para position; preferably at least nonylphenol. The average number of phenolic nuclei per molecule of preferred nonylphenol-aldehyde resin is preferably superior to 6 and inferior or equal to 25, more preferably comprised within the range 8 to 17, and advantageously within the range 9 to 16 phenolic nuclei per molecule. The average number of phenolic nuclei per molecule can be determined by RMN or GPC.
According to a preferred embodiment, the modified alkylphenol-aldehyde resins according to the invention can be obtained from at least one aldehyde and/or one ketone chosen from formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, 2-ethyl hexanal, benzaldehyde, acetone, preferably at least formaldehyde. According to a preferred embodiment, the modified alkylphenol-aldehyde resins according to the invention can be obtained from at least one alkylamine having at least one primary amine group, and advantageously at least one compound, all the amine groups of which are primary amines. According to a preferred embodiment, the modified alkylphenol-aldehyde resins according to the invention can be obtained from at least one alkylamine with an aliphatic chain having between 12 and 24 carbon atoms, preferably between 12 and 22 carbon atoms. According to a particularly preferred embodiment, the modified alkylphenol-aldehyde resins according to the invention can be obtained from at least one alkylamine having at least one primary amine group and comprising an aliphatic chain having between 12 and 24 carbon atoms, preferably between 12 and 20 carbon atoms.
The commercially-available alkylamines are in general not pure compounds but mixtures. Among the commercially-available alkylamines which are suitable, there can in particular be mentioned the following alkylamines with an aliphatic chain marketed under the names: Noram®, Duomeen®, Dinoram®, Trinoram®, Triameen®, Armeen®, Polyram®, Lilamin® and Cemulcat®. The viscosity of the modified alkylphenol-aldehyde condensation resins according to the invention diluted with 30% by mass of aromatic solvent measured at 50° C. using a dynamic rheometer with a shear rate of 100 s−1 is in general comprised between 1,000 and 10,000 mPa·s, preferably between 1,500 and 6,000 mPa·s, and advantageously between 2,500 and 5,000 mPa·s.
The modified alkylphenol-aldehyde resins according to the invention can be used as additives for improving the low temperature properties of fuel oils and of oil distillates of petroleum origin and/or of renewable origin, and more particularly of the middle distillates the boiling temperature range of which is in the majority comprised between 100 and 500° C. Crude oils and the middle distillates, obtained from crude oils of petroleum origin by distillation, such as gas oil, diesel motor fuel or fuel oil domestic, contain, depending on the origin of the crude oil, different quantities of n-alkanes or n-paraffins which by lowering the temperature, typically below 0° C., crystallize out as lamellar crystals which have tendency to agglomerate: there is then a deterioration in the flow characteristics of the oils and distillates; difficulties occur during transport, storage and/or use of the oil or fuel: the wax crystals having tendency to block pipes, fuel lines, pumps and filters, for example in automobile vehicle fuel systems.
In winter or in conditions of use of the oil or the distillate at a temperature below 0° C., the crystallization phenomena can lead to deposits on the pipe walls, even a complete blockage. These problems are well known in the field of motor fuels and liquid hydrocarbon fuels where numerous additives or mixtures of additives have been proposed and are marketed for reducing the size of the wax crystals and/or changing their shape and/or preventing their formation. The smallest possible crystal size is preferred as it minimizes the risks of blockage or clogging the filter. The usual agents for improving the flow of crude oils and middle distillates are co- and ter-polymers of ethylene and vinyl and/or acrylic ester(s) alone or in a mixture with low molecular weight oil-soluble compounds or polymers which contain one or more ester, amide, imide, ammonium groups substituted by at least one alkyl chain.
Apart from improving the flow of the oil and the distillate, another purpose of the additives for improving the flow is to ensure the dispersion of the wax crystals so as to delay or prevent the settling of the wax crystals and therefore the formation of a layer rich in waxes at the bottom of receptacles, vessels or storage tanks; these additives for dispersing waxes are called WASA (acronym for the term wax anti-settling additive). The inventors have noted that the modified alkylphenol-aldehyde resins according to the invention have a wax dispersing activity: they make it possible to limit the settling of the crystallized waxes without further addition of dispersing agent. Thus a mixture of co- and/or ter-polymer(s) of ethylene and vinyl ester(s) and/or acrylic ester(s) with at least one modified alkylphenol-aldehyde resin which is a subject of the invention makes it possible to avoid the settling of wax crystals at low temperature.
The modified alkylphenol-aldehyde resins according to the invention can be used for improving the low temperature behaviour and in particular the dispersion of the waxes in motor fuels and liquid fuels based on hydrocarbon oils and middle distillates the range of boiling temperatures of which is in the majority comprised between 100 and 500° C. In particular the motor fuels and liquid fuels to which the modified alkylphenol-aldehyde resins according to the invention are added are for example jet fuel, gas oil or motor diesel fuel, fuel oil domestic, heavy fuel oil which have a boiling range from 120 to 500° C., preferably 140 to 400° C. In general the sulphur content of the compositions of motor fuels and liquid fuels is less than 5,000 ppm, preferably less than 500 ppm, and more preferentially less than 50 ppm, even less than 10 ppm and advantageously with no sulphur, in particular for the motor fuels of gas oil and jet type.
Another object of the present invention is compositions of motor fuels and liquid hydrocarbon fuels the boiling temperatures range of which is in the majority comprised between 100 and 500° C. comprising:                a majority proportion of hydrocarbon compounds and/or vegetable and/or animal oils and/or their esters of oils and/or biodiesels of animal and/or vegetable origin        and a minority proportion, preferably comprised between 5 and 5,000 ppm by mass of at least one of the resins according to the invention.        
The motor fuels and liquid fuels comprise the middle distillates with a boiling temperature comprised between 100 and 500° C.; their initial crystallization temperature ICT is often greater than or equal to −20° C., in general comprised between −15° C. and +10° C. These distillates can for example be chosen from the distillates obtained by direct distillation of crude hydrocarbons, the distillates from vacuum distillation, hydrotreated distillates, distillates originating from catalytic cracking and/or hydrocracking of distillates under vacuum, distillates resulting from conversion processes of ARDS (atmospheric residue desulphuration) type and/or visbreaking, distillates originating from upgrading of Fischer-Tropsch cuts, distillates resulting from BTL (biomass to liquid) conversion of vegetable and/or animal biomass, and/or their mixtures. The motor fuels and liquid fuels can also contain distillates originating from refining operations which are more complex than those originating from the direct distillation of the hydrocarbons which can for example originate from cracking, hydrocracking and/or catalytic cracking processes and visbreaking processes.
The motor fuels and liquid fuels can also contain new sources of distillates, among which there can in particular be mentioned:                the heaviest cuts originating from the cracking and visbreaking processes with a high concentration of heavy paraffins, comprising more than 18 carbon atoms,        synthetic distillates originating from the conversion of gas such as those originating from the Fischer Tropsch process,        synthetic distillates resulting from the treatment of biomass of vegetable and/or animal origin, such as in particular NExBTL,        and the vegetable and/or animal oils and/or their esters such as methyl or ethyl esters of vegetable oils (MEVO, EEVO),        hydrotreated and/or hydrocracked and/or hydrodeoxygenated (HDO) vegetable and/or animal oils,        or also biodiesels of animal and/or vegetable origin.These new motor fuel and fuel bases can be used alone or in a mixture with standard petroleum middle distillates as a motor fuel base and/or fuel oil domestic base; they generally comprise long paraffin chains greater than or equal to 10 carbon atoms and preferably C14 to C30.        
According to an embodiment of the invention, the modified alkylphenol-aldehyde resins according to the invention are used in motor fuels and liquid fuels in combination with at least one additive improving the low-temperature flow, such as the co-polymers and ter-polymers of ethylene and vinyl and/or acrylic ester(s). By way of example of additives improving the low-temperature flow of copolymer type, there can be mentioned the EVAs (copolymers of ethylene and vinyl acetate); as examples of ter-polymers, there can be mentioned those which are described in EP 1 692 196, WO09/106743, WO09/106744. According to an embodiment of the invention, the modified alkylphenol-aldehyde resins according to the invention can be used in combination with at least one wax-dispersing additive different from the modified alkylphenol-aldehyde resins according to the invention. Among the wax-dispersing additives, there can be mentioned the polar nitrogenous compounds.
According to a preferred embodiment, the modified alkylphenol-aldehyde resins according to the invention are used in motor fuels and liquid fuels without the addition of dispersant, chosen for example from the polar nitrogenous compounds. According to a preferred embodiment, the modified alkylphenol-aldehyde resins according to the invention are used in combination with at least one wax-dispersing additive different from the modified alkylphenol-aldehyde resins according to the invention, such as for example an unmodified alkylphenol-aldehyde resin and optionally with at least one additive improving the low-temperature flow.
According to a preferred embodiment, each additive separately or the mixtures of additives are dissolved or dispersed with one or more solvent or dispersing agents before adding to the oils or the distillates. Solvent or dispersing agents are for example aliphatic and/or aromatic hydrocarbons or mixtures of hydrocarbons, for example fractions of gasoline, kerosene, decane, pentadecane, toluene, xylene, and/or ethylbenzene and/or mixtures of commercial solvents such as Solvarex 10, Solvarex LN, Solvent Naphtha, Shellsol AB, Shellsol D, Solvesso 150, Solvesso 150 ND, Solvesso 200, Exxsol, ISOPAR. Polar dissolution adjuvants, such as 2-ethylhexanol, decanol, isodecanol and/or isotridecanol can also be added.
Apart from the additives mentioned in the embodiments above, namely the modified alkylphenol-aldehyde resins according to the invention, the additives for improving the low-temperature flow, the wax-dispersing additives, other additives can also be added such as corrosion inhibiting agents, detergent additives, anti-clouding agents, additives improving the conductivity, colorants, reodorants, lubricity or lubricating additives, etc. Among these other additives, there can be particularly mentioned:                a) the procetane additives, in particular (but not limitatively) chosen from the alkyl nitrates, preferably 2-ethyl hexyl nitrate, the aroyl peroxides, preferably benzyl peroxide, and alkyl peroxides, preferably di ter-butyl peroxide;        b) the anti-foam additives, in particular (but not limitatively) chosen from the polysiloxanes, the oxyalkylated polysiloxanes, and the fatty acid amides originating from vegetable or animal oils; examples of such additives are given in EP 663 000, and EP 736 590;        c) the detergent and/or anti-corrosion additives, in particular (but not limitatively) chosen from the group constituted by the amines, succinimides, alkenylsuccinimides, polyalkylamines, polyalkyl polyamines and polyetheramines; examples of such additives are given in EP 938 535.        d) lubricity additives or anti-wear agent, in particular (but not limitatively) chosen from the group constituted by the fatty acids and their ester or amide derivatives, in particular glycerol monooleate, and mono- and polycyclic carboxylic acid derivatives; examples of such additives are given in the following documents: EP 680 506, EP 860 494, WO 98/04656, EP 915 944, FR 2 772 783, FR 2 772 784.        e) the cloud point additives, in particular (but not limitatively) chosen from the group constituted by the long-chain olefin/(meth)acrylic ester/maleimide terpolymers, and fumaric/maleic acid ester polymers. Examples of such additives are given in EP 71 513, EP 100 248, FR 2 528 051, FR 2 528 423, EP 112 195, EP 1 727 58, EP 271 385, EP 291 367;        f) anti-settling additives and/or wax dispersants in particular (but not limitatively) chosen from the group constituted by (meth)acrylic acid/polyamine-amidified alkyl(meth)acrylate copolymers, polyamine alkenylsuccinimides, the derivatives of phthalamic acid and of double-chain fatty amine; alkylphenol/aldehyde resins that differ from the alkylphenol/aldehyde resins according to the invention; Examples of such additives are given in EP 261 959, EP 593 331, EP 674 689, EP 327 423, EP 512 889, EP 832 172; U.S. Patent Publication No. 2005/0223631; U.S. Pat. No. 5,998,530; WO 93/14178;        g) the cold operability multi-functional additives chosen from the group constituted by the polymers based on olefin and alkenyl nitrate as described in EP 573 490;        h) other additives improving resistance to cold and filterability (CFI), such as the EVA and/or EVP copolymers;        i) anti-oxidants of hindered phenolic type or amines of alkylated paraphenylene diamine type;        j) metal passivators, such as triazoles, alkylated benzotriazoles;        k) metal sequestering agents such as disalicylidene propane diamine (DMD)        l) acidity neutralizers such as cyclic alkylamines;These other additives as well as the modified alkylphenol-aldehyde resins according to the invention are in general added in a quantity ranging from 5 to 1,000 ppm (each)        